General Users are granted beam time through a peer review proposal process. They may use beamlines and endstations provided by the ALS or the Participating Research Team (PRT) that operates the beamline.

Before Submitting a Proposal

Review the ALS Beamlines Directory to learn about the research capabilities of individual beamlines at the ALS. Contact the beamline scientist or the local contact listed in the tables, for additional information about the beamline.

General User Proposals (GUPs) generally remain active for two years (four cycles) or until the number of shifts recommended by the Proposal Study Panels (PSP) for the life of the proposal have been used. Users may decide whether to submit a new proposal or make a beam time request on an active proposal based on the cutoff score for that beamline.

Please note that proposal scores may be adjusted in subsequent cycles, as follows

Proposals that are allocated beam time in the first cycle, will retain the same score.

Proposals that do not obtain beam time in the first cycle will have their score ‘improved’ (score decreased by 0.2). This should increase the probability of obtaining beam time for proposals close to the cutoff. The aim is to help these users to write an improved proposal.

If a proposal with an improved score is allocated beam time the score will revert to the original score for future cycles.

Proposal Review and Scoring Process

All submitted proposals are reviewed by:

ALS staff for technical feasibility and safety

Up to four external reviewers

the PSP, which determines the final scores of proposals and makes recommendations concerning requested beam time

GUPs are scored on a scale of one to five, where one is the highest score. Beam time is then assigned based on each proposal's ranking in relation to all other proposals for a given beamline. Proposals for oversubscribed beamlines may be moved to alternative beamlines with appropriate capability. See proposal score statistics for the current cycle.

Allocating Beam Time

Once all proposals have been reviewed and assigned a score, beam time for general users is allocated by the ALS User Office in consultation with the beamline scientist. This process is overseen by the ALS Deputy Division Director for Science. The available beam time is allocated according to the rank order of score, beginning with the best score and continuing until the beam time allotment for general users has been met.

Notification ProcessResponses to the proposals are sent via email approximately three months after the submission deadline. Each proposal is given a numeric rating that is communicated to the PI and the experimental lead, along with comments from the external reviewers and PSP. For most beamlines, a cutoff score is determined, below which no beam time is allocated. For each beamline the cutoff score will be published on the Proposal Score Statistics Web page.

Scheduling Beam Time

Beam time schedules are finalized by the beamline scientist in consultation with users. See the ALS Beamlines Directory for beamline scientist contact information.

Access to the Molecular Foundry

It is possible to request access to the Molecular Foundry, a national nanoscience research facility at Berkeley Lab, to assist meeting certain minimal needs of an ALS proposal. Users should review these guidelines before completing their proposal.